• Steel and Composite Structures
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• 제28권2호
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• pp.209-221
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• 2018

An empirical and efficient method is presented for calculating the dynamic increase factor to amplify the applied loads on the affected bays of a steel frame structure with semi-rigid connections. The nonlinear static alternate path analysis is used to evaluate the dynamic responses. First, the polynomial models of the extended end plate and the top and seat connection are modified, and the proposed polynomial model of the flush end plate connection shows good agreement as compared with experimental results. Next, a beam model with nonlinear spring elements and plastic hinges is utilized to incorporate the combined effect of connection flexibility and material nonlinearity. A new step-by-step analysis procedure is established to obtain quickly the dynamic increase factor based on a combination of the pushdown analysis and nonlinear dynamic analysis. Finally, the modified dynamic increase factor equation, defined as a function of the maximum ratio value of energy demand to energy capacity of an affected beam, is derived by curve fitting data points generated by the different analysis cases with different column removal scenarios and five types of semi-rigid connections.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.334-337
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• 2004

Groundwater chemistry in Namwon area, Korea, was investigated to understand the contribution of geochemical processes on groundwater chemistry. For this study, a total of 279 groundwater samples were collected from 93 wells distributed over the study area. Higher concentrations of major ions are generally encountered in the shallow alluvial wells, suggesting that these chemicals are originated from the surface contamination sources. Mass balance analysis based on reaction stoichiometry reveals that the water chemistry is regulated by three major chemical processes: weathering of silicate/ carbonate minerals, input of C1/SO$_4$ salts, and nitrate generating processes. The results show that mineral weathering is the most dominating factor regulating the groundwater chemistry. However, the groundwaters with the higher salt concentration indicate the larger mineral weathering effect, suggesting that some part of the mineral weathering effect is also associated with the anthropogenic activities such as limes applied to the cultivated lands, carbonates (CaCO$_3$) in the cement materials.

• Plant Biotechnology Reports
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• 제3권2호
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• pp.127-134
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• 2009

Members of the NAM-ATAF-CUC (NAC) protein family are plant-specific transcription factors that contain a highly conserved N-terminal NAC-domain and diverse C-terminal regions. They have been implicated in plant development and abiotic stress responses. To identify interacters of rice NAC-domain proteins (OsNACs), we performed yeast two-hybrid screening of rice cDNA library using OsNAC5 as a bait, and the results showed that OsNAC5 interacts with other OsNACs including itself. To delineate an interacting domain, a series of deletion constructs of four OsNACs were made and transformed into yeast in various combinations. The results revealed that the conserved NAC domain of OsNACs plays a primary role in homodimer and heterodimer formation, and a part of C-terminal sequence is also necessary for the interaction. In vitro pull-down assays using recombinant OsNAC proteins verified the dimer formations, together suggesting that OsNACs may act by forming homodimers and/or heterodimers in plants.

• Environmental Engineering Research
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• 제24권1호
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• pp.107-116
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• 2019

Nitrogen removal, nitrous oxide ($N_2O$) emission and microbial community in sequencing batch and continuous-flow intermittent aeration processes were investigated. Two sequencing batch reactors (SBRs) and two continuous-flow multiple anoxic and aerobic reactors (CMRs) were operated under high dissolved oxygen (DO) (SBR-H and CMR-H) and low DO (SBR-L and CMR-L) concentrations, respectively. Nitrogen removal was enhanced under CMR and low DO conditions (CMR-L). The highest total inorganic nitrogen removal efficiency of 91.5% was achieved. Higher nitrifying and denitrifying activities in SBRs were observed. CMRs possessed higher $N_2O$ emission factors during nitrification in the presence of organics, with the highest $N_2O$ emission factor of 60.7% in CMR-L. SBR and low DO conditions promoted $N_2O$ emission during denitrification. CMR systems had higher microbial diversity. Candidatus Accumulibacter, Nitrosomonadaceae and putative denitrifiers ($N_2O$ reducers and producers) were responsible for $N_2O$ emission.

• BMB Reports
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• 제49권1호
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• pp.37-44
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• 2016

Spectraplakins are crucially important communicators, linking cytoskeletal components to each other and cellular junctions. Microtubule actin crosslinking factor 1 (MACF1), also known as actin crosslinking family 7 (ACF7), is a member of the spectraplakin family. It is expressed in numerous tissues and cells as one extensively studied spectraplakin. MACF1 has several isoforms with unique structures and well-known function to be able to crosslink F-actin and microtubules. MACF1 is one versatile spectraplakin with various functions in cell processes, embryo development, tissue-specific functions, and human diseases. The importance of MACF1 has become more apparent in recent years. Here, we summarize the current knowledge on the presence and function of MACF1 and provide perspectives on future research of MACF1 based on our studies and others. [BMB Reports 2016; 49(1): 37-44]

• 한국직업건강간호학회지
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• 제6권1호
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• pp.14-22
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• 1997

This study was designed to determine anxiety factors and levels of anxiety of foreign industrial workers. One hundred and seventy five workers were researched who were working in Guro Working Complex, Ansan City and Sungnam City Working Complex asking 60 questionnaires from Feb. 25, 1996 to April 12, 1996. The results were as follows ; 1. The 30.3% of foreign workers were from Nepal, 17.7% from Bangladesh, 10.9% from SriLanka, 14. 9% from Philippines, 1.1% from Ghana. 80% of foreign workers were male, 11.1% were single and most of them were in the age from 25 to 34. 37.1% of foreign workers had not lived in Korea less than 12 months, 58.8% graduated from college, 33.7% from high school, and more than half lived in a dormitory. 2. On the anxiety level related to subject workers' general characteristics, the anxiety level from Nepal recorded the highest point 2.70 statistically showing a significant difference(p=0.0003). On the physical anxiety level, the workers from Nepal recorded a significantly low point comparing with Jamaica, Burma, Vietnam and Nigeria(p=0.01). 3. Emotional anxiety level marked the highest on the workers living as a tenant comparing with the workers in dormitory. 4. On anxiety factors, the emotional anxiety recoded the highest, the social anxiety and the somatic anxiety. 5. On the relation between the anxiety factor, the somatic anxiety factor had a relation with emotional, environmental, and occupational factors and on the other relation between the anxiety factor and emotional factor had a relation with environmental, social, cultural factors. Moreover, the environmental factor had a relation with the cultural factor, social factor had a relation with the cultural factor, and cultural factor was related to the occupational factor.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.183-183
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• 2017

Pan evaporation (Epan) is an important indicator of water and energy balance. Despite global warming, decreasing annual Epan has been reported across different continents over last decades, which is claimed as pan evaporation paradox. However, such trend is not necessarily found in seasonal data because the level of contributions on Epan vary among meteorological components. This study investigates long-term trend in seasonal pan evaporation from 1908 to 2016 across South Korea. Meteorological variables including air temperature (Tair), wind speed (U), vapor pressure deficit (VPD), and solar radiation (Rs) are selected to quantify the effects of individual contributing factor to Epan. We found overall decreasing trend in Epan, which agrees with earlier studies. However, mixed tendencies between seasons due to variation of dominant factor contributing Epan were found. We also evaluated the reference evapotranspiration based on Penman-Monteith method and compared this with Epan to better understand the physics behind the evaporation paradox.

• 한국환경과학회지
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• 제12권7호
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• pp.763-774
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• 2003

This study was conducted to design long and short forms of reliable and valid Likert-type scales to measure environmental attitudes of Korean junior high school students. 8 tests were applied to the construction of a 32-item long form and 8-item short form of the scale. Two scales were field tested on 469 respondents consisting of male and female students in urban and rural areas and students participating in environmental programs. The 32-item scale was revealed to be highly reliable, content and construct valid. Reliability and homogeneity of this scale were evidenced by 0.92 coefficient alpha and positive interitem correlation values ranging from 0.10 to 0.52. Factor analysis and known-group comparison showed the sufficient validity of long form scale. Reliability and validity of short form scale were also evidenced by good results of 8 test analyses. The long and short forms were strongly correlated, ${\gamma}$-value of 0.90. Consequently, both long form and short form scales were evidenced very reliable and valid in measuring environmental attitudes of junior high school students in Korea. They can be useful for a variety of survey conditions and constraints and testing environmental attitude.

• 한국과학교육학회지
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• 제13권2호
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• pp.272-281
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• 1993

The purpose of this study was. to develop a valid and reliable Likert-type scale to assess middle school students' attitude toward environmental pollution. The evaluation categories of this instrument were cognition and conaction levels. Initially, 42 statements (29 statements for cognition level and 13 statements for conaction level) were framed. This pilot instrument was administered to 1015 middle school students. To select valid and reliable statements, the 42 initial statements were analyzed by item mean, standard deviation, and response distribution. In addition, the emotional intensity: of each statement was judged. As a result, 22 final statements (14 statements for cognition level and 8 statements for conaction level) were developed. Cronbach alpha coefficient of the instrument was 0.76 with a range of item-total correlation from 0.229 to 0.488. Factor analysis was done to explore the potential constructs of this instrument. As a result, six factors were extracted. Those factors were identified as "Conaction to prevent environmental pollution", "Confrontation with the enterprise which causes environmental pollution", "Voluntary inclination to participate in the group which prevents environmental pollution", "Discussion on environmental pollution", "Environmental pollution and interests", and "Everyday sources of environmental pollution".

• 한국환경과학회지
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• 제25권2호
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• pp.281-288
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• 2016

After analyzing of heating value of four kinds of RDF, the RDF-D has the highest heating value, was chosen to be mixed with carbonized sludge by different ratio. The 85%:15% ratio, which has the highest efficiency, was analyzed with thermogravimetric and pyrolysis kinetics. Applying of Kissinger method, activation energy was obtained from slope which is calculated from relation of ln(${\beta}/T^2{_m}$) and $1/T_m$. The kinetic parameters obtained from Kissinger method were 46.06 kJ/mol of RDF, 55.99 kJ/mol of carbonized sludge and 40.68 kJ/mol of mixture of RDF and carbonized sludge. The mixture of RDF and carbonized sludge has the lowest activation energy and frequency factor, during thermal decomposition reaction it has the slowest reaction rate and needs the lowest energy. Although activation energy with pyrolysis of RDF was irregularly scattered, it showed that activation energy was stabilized by co-pyrolysis of RDF and additives(Carbonized Sludge).